Pressure equalizer for dual tyres of landcraft or aircraft



Sept. 23, 1969 GlovANNl DALL'oLlo com-Rl PRESSURE EQUALIZER FOR DUAL TYRES 0F LANDCRAFT OR AIRCRAFT Filed Nov. 9, 1967 B 39 'N 47 w' l 7&6 gf-g M1410! A i T 7 e 15 33 41 437 31 1444 5 l n En INVENTOR:

my En i United States Patent O 3,468,162 PRESSURE EQUALIZER FOR DUAL TYRES OF LANDCRAFT OR AIRCRAFT Giovanni DallOlio Contri, Via Appollonio 48, Brescia, Italy Filed Nov. 9, 1967, Ser. No. 681,840 Claims priority, application Italy, Nov. 15, 1966, 29,977/ 66 Int. Cl. B60c 23/10 U.S. Cl. 73-146.3 3 Claims ABSTRACT OF THE DISCLOSURE A pressure equalizing device for dual tyres of vehicles is disclosed, in which a flexible diaphragm is provided, which can be dellected in one direction by the pressure obtaining in the tyres and in the opposite direction under the bias of a spring, the movements of said diaphragm being displayed through a window which shows differently coloured areas of plate according to the inflation conditions of said tyres, means being provided to measure the pressure obtaining in said tyres and for preadjusting it to a preselected value, signalling means of an electrical nature being further provided to give a warning signal to the vehicles driver.

This invention relates to a device, which can be applied to a air of tyres (dual tyres) for vehicles (heavy duty landcraft in general and aircraft), said device enabling the dual tyres, by connecting them together, to adapt themselves to the road surface as if they were a single large tyre, by reacting with the resiliency of the whole air mass contained in both of them. v

This invention has, as its object, that of improving, in an equalizing device of the kind referred to above, the means adapted to signal, at every instant of time, the status of communication between the two tyres, or the lack of communication therebetween whenever, for any accidental reason, a pressure drop has taken place in either type, exceeding a preselected limit.

The device according to the present invention comprises: a casing, a chamber in said casing, a ilexible diaphragm which closes said chamber, a spring biassing a face of said diaphragm, means for adjusting from the outside the bias applied by said spring for deecting said diaphragm towards the interior of said chamber, a pair of ducts within said casing, each duct being susceptible of being connected at either end to either tyre and having its other end opening into said chamber through a port t convey compressed air from said tyres towards said chember so as to deflect said diaphragm towards the exterior of said chamber, said two ports being aranged on a plane substantially parallel to the plane of said diaphragm so as to have said ports closed by said diaphragm when the pressure in Vsaid chamber drops below said preselected value as determined by said spring, a rod which can slide axially and has an end contacting said diaphragm with the agency of a retaining cap and flexible cup as a sealtighmess member, and its other end contacting the shorter arm of a lever acting on a second lever which in turn is active, against the bias of a return spring, upon a signalling member, the latter consisting of a plate allowed to slide on the plane of, and below, a window formed through the casing and which can be viewed from the outside, said plate being divided into two diierently coloured areas, said areas being alternatingly visible beneath said window.

The accompanying drawing is a diagrammatical showing of an embodiment of the invention device.

In the drawing:

3,468,162 Patented Sept. 23, 1969 ICC FIGURE 1 is a front view of the device.

FIGURE 2 is a cross-sectional view taken along a plane which is perpendicular to the plane of FIG. 1.

FIGURE 3 shows adetail, and

FIGURE 4 is a detail shown in plan view.

The presser equalizer shown in the drawing comprises a casing 20 which encloses all the component parts.

To the body 20 is screwably atlixed a ring 21 which has a right screw thread on its outer peripheral surface and a left, high-speed pitch, screw thread on its inner periphery, to which a hood 22 is screwed: the latter has, in central position, a tapped hole through which a screw 25 is mounted, which is adapted to lock said hood 22 and a lid 24, integral with a handle 23, together. In addition, the hood 22 and the lid 24 have two respective sets of small teeth 51, arranged on a circle and meshing with one another, so that, by virtue of said teeth and said screw 25, the handle 23 and the hood 22 form an integral unit which can be rotated, screwably, within the ring 21, the latter remaining, conversely, in xed position with respect to the casing 20. The cylindrical sidewall of the lid 24 is received by an annular seat 38 of the casing 20, in which it can both be rotated and translated (following the motion of hood 22).

In the casing 20 a chamber C is formed, which is closed, on one side, by a resilient diaphragm 26 (of rubber or rubber-like material), clamped between a face of the casing 20 and a ring 27, the latter being locked, in turn, by the metal ring 21. Between the diaphragm 26 and the hood 22 a spring 28 is active, which tends to bias the diaphragm so as to reduce the volume of the charnber C. The spring 28 biasses said diaphragm through a cup 50` housed in an annular wall 52 of ring 27 which guides the cup in its axial motion. It is apparent that, by rotating the handle 23, thus causing the axial location of the hood 22 to be varied, also the bias of the spring 28 against the diaphragm 26 is varied.

A cylindrical perforation of the casing 20 houses a cylindrical retaining cap 1 which rests, with its bottom, on said diaphragm; a resilient cup 2 (of rubber or the like) is clamped in the casing 20 by a threaded plug 15 which, screwed into said casing 20, locks a ilange of the cup against face of said casing 20, a washer 29 being catered for between said plug and said flange, so as to avoid friction between said plug and said flange.

The axially bored plug 15 has a rod 3 passing therethrough which contacts at one end, the cup 2, the latter contacting, in turn, a projection 30 of the retaining cup 1. Said cup 2 provides the seal-tightness between the chamber C and the space B. To the casing 20 is atixed a framing 11, by means of a screw 14: to said framing are pivotally connected two levers 4 and 5 by means of the respective pivots 31 and 32.

Lever 4 carries at one end an adjustment screw 33 in which is universally received an end of said rod 3.

Said lever 4 contacts, at its other end, an arm of said lever 5; the latter is adapted to act, with its two prongs which are placed side by side and form lits other end, on a wall 34 solid with a plate 6 which can slide along two parallel ways 37, the latter being in fixed position with regard to the casing 20.

To the body 20 is ailixed a wall 39 having a window 40 of rectangular outline, through which it is possible to see, according to the one of the two equilibrium positions of the plate 6 which is involved, either area of the two diierently coloured areas M and N, for example red or white, of said plate.

A spring 7 is aixed with its two ends to the wall 34 and to a member 41 (in xed position with respect to the casing 20), said spring tending to urge the plate 6 3 in such a direction as to display the white area N of said plate beneath the window 40.

Two ducts 42 (one of which only is shown in the drawing) communicate each with the respective tyre of the dual tyre assembly (that is with the two individual component tyres), both ducts being in communication with 'the chamber C, wherein the two edges 43 of said ducts are coplanar. In FIG. 1, S and D (left and right) connote the two ducts 42 leading to the individual tyres. The drawing shows also an electric conductor wire 13, an end of which is affixed to an insulating clamp 16: to the latter clamp can ze aixed, from the outside, a conductor wire 13' which can be connected to an apparatus, possibly installed on the vehicle, for sound and/ or luminous signals as will be explained in more detail hereinafter.

The lever 5 aforementioned is adapted to contact, with one of its ends, the wire 13 thus completing a circuit for energizing said signalling device. An adjustment screw 12, made of a dielectric material, is screwed in the portion 44 of the frame 11 and contacts the wire 13 so as to adjust the position thereof. A glass-locking ring nut is screwed on the screw-thread 47. The numeral 46 indicates the pointer of a pressure-gauge (not shown to simplify the drawing) which is housed within the space B and adapted to indicate the pressure obtaining in the chamber C. The subject device is aixed to a wheel of the vehicle concerned by means of the portion 48 of the casing 20, said portion 48 being fastened, by bolts, to a plate aixed to the wheel hub and carrying, for enabling the portion 48 to be aixed thereto, two bores corresponding to the tapped bores 49 of said portion 48. Lastly, the numeral 53 indicates a blind adapter to which one of the ducts 42 is affixed, either S or D, which has been disconnected from the corresponding individual tyre when, being either tyre punctured, it is desired to inflate the other one only (through I).

Assume now that the two individual tyres are inflated to their irregular pressure: this pressure, via the ducts 42 which connect the respective individual tyres with the chamber C, is active on the diaphragm 26. More accurately, said diaphragm undergoes, on one side, said pressure of the tyres (Le. the pressure obtaining within the chamber C) and, on the opposite side, the pressure given by the bias of the spring 28 which is a function, as out lined above, of the axial position of the hood 22, that is, of the angular position of the handle 23. The pressure of the tyres tends to withdraw the diaphragm 26 from the edges 43 of the ducts 42 whereas the bias of the spring 28 tends to press the diaphragm against said edges to cut off the ducts 42 and undo the communication between the two tyres. Now, said handle 23 can be so angularly positioned as to cause the bias of the spring 28 to be inspicient to urge the diaphragm 26 against the ducts 42 to plug them: thus, the diaphragm thus remaining spaced apart by a certain gap from the ports 43, through which the ducts open into the chamber C. It is apparent that, whenever the pressure in chamber C drops under a preselected limiting value, the diaphragm 26, under the predominant bias of the spring 28, will rest on the ports 43 thus closing the ducts 42. It is likewise apparent that, should the diaphragm 26 be spaced a short distance apart from the ports 43, a slight pressure drop in C is enough to cause said closing action to take place. The position of the handle 23 aforementioned thus indicates, on a dial from 2 to 7 (on the right, as viewed in FIG. l), the value at which the pressure in the chamber C should drop to determine the closure of the ducts 42. This value can be varied by rotating said handle. The pressure drop within the chamber C takes place when either individual tyre has become air-pervious: if so, air leaks into the atmosphere from a tyre but the pressure is equally decreased in both tyres, these being intercommunicating. As the pressure in C is becoming smaller, at a certain stage, as aforesaid, the closure of the conduits takes place by the agency of the diaphragm 26.

If, for example, there is in the dual tyre (and thus in C) a pressure of 6 atmospheres, as shown, on the dial from 1 to 9 (in the left portion as viewed in FIG. 1) by the pointer 46 of the gauge, and the handle 23 is in the position live (5) of said dial from 2 to 7, in the case of a pressure drop in a tyre, the ducts 42 will be cut off by the diaphragm 26 as soon as the pressure in the two tyres (and thus in C) has fallen to 5 atmospheres. Once the ducts 42. have been cut off, the two individual tyres are no longer in communication s o that, while either tyre continues to flatten, the other one stays at the preselected pressure of 5 atmospheres. The vehicle is thus enabled to continue its journey on one of the two individual tyres until the other one is replaced or repaired (that which should be made as soon as practicable). In practice, when the tyres are inllated by introducing compressed air through the duct J, the handle 23 is left in the preselected position, e.g. on the position ve; the inflow of compressed air keeps the ports 43 spaced from the diaphragm 26 so that the tyres are inflated through the ducts 42. Once the preselected pressure, for example 6 atmospheres, has been attained in the tyres, the feed hose (which was connected to the duct J) is disconnected and, at this stage, the ducts 42 are automatically cut ol by the diaphragm 26: after closing the duct J with a cap 45, the handle 43 is brought to the position at which the spring 28 impresses a minimum bias on the diaphragm 26 and, by so doing, the communication between the two ducts 42 is restored (the diaphragm is separated from the ports 43): then the handle 23 is brought to its preselected position, such'as, for example the position 5 aforementioned. When in C a pressure obtains which is adapted to keep the diaphragm 26 withdrawn from the edges 43 of the ducts, that is to maintain a communication between the two paired tyres, the spring 7 holds the plate 6 in the position (on the left, as viewed in FIG. 2) in which the white area N of said plate is beneath said window 10 and can be inspected therethrough. When, conversely, a leakage occurs in a tyre, with the ensuing displacement of the diaphragm 26 towards the ports 43, the diaphragm itself urges the retaining cup 1 and the latter, through the cup 2, urges the rod 3 upwards, as viewed in FIG. 2. The lever 4 thus effects a slight rotation and acts with its longer arm, on said lever 5. This lever, in turn, by rotating, urges the plate 6, against the bias of the spring 7, shifting under the window 40 the red area M of the plate, which can be clearly seen through said window.

By displacing the handle 26, in addition, the lever 5 contacts with one end said wire 13 thus completing the circuit which, in turn, actuates the device for signalling to the driver with optical and/or acoustical means, that a cutol has occurred.

Upon repairing the tyre and inliating (for example to 6 atmospheres) the two paired tyres as aforesaid, the diaphragm 26 is again separated from the ports 43 of the ducts and the retaining cup 1 can be shifted (downwardly as viewed in FIG. 2) so that the spring 7 causes the plate to display a white area with the area N under the window 40.

In the light of the foregoing, it is clear that an observer, looking at the device (on the ground when the vehicle is stationary), can learn, according to whether white or red is displayed through the window 40, whether the two paired tyres are in mutual communication or not.

If the device displays a red signal and it is desired to know which tyre is leaking, the handle 23 can be displaced in the direction so as to reduce the bias of the spring 28 so as to cause a flick of the pressure pointer: the direction of said flick indicates which is the leaking tyre.

What is claimed is:

1. A device for signalling the pressure and possible leakages for intercommunicating tyres of landcraft or aircraft, comprising a casing, a chamber in said casing,

a flexible diaphragm which closes said chamber, a spring biassing a face of said diaphragm, means for adjusting from the outside the bias applied by said spring for deecting said diaphragm towards the interior of said chamber, a pair of ducts within said casing, each duct being susceptible of being connected at either end to either tyre and having its other end opening into said chamber through a port to convey compressed air from said tyres towards said chamber so as to deflect said diaphragm towards the exterior of said chamber, said two ports being arranged on a plane substantially parallel to the plane of said diaphragm so as to have said ports closed by said diaphragm when the pressure in said chamber drops below a preselected value as determined by said spring; a rod which can slide axially and has an end contacting said diaphragm with the agency of a retaining cap and a exible cup as a sealing member, and its other end contacting the shorter arm of a lever acting on a second lever which in turn is active, against the bias of a return spring, upon a signalling member, the latter consisting of a plate allowed to slide on the plane of and below, a window formed through the casing and which can be viewed from the outside, said plate being divided into two differently coloured areas, said areas being alternatingly visible beneath said window.

2. A device according to claim 1, characterized in that the chamber into Awhich open the two ducts in communication with the two individual tyres communicates also with a pressure gauge whose dial is aixed to said casing along with a graduated scale for indicating the pressures obtaining within said chamber, carries a second graduated scale for indicating the bias furnished by said spring once that the adjustment has been made.

3. A device according to claim 1, characterized in that in the vicinity of either arm of either lever interposed between said rod and said plate an electric conductor is arranged having a gap adjustable by means of a specially provided screw, said conductor being capable of connection, by an end issuing from said casing, through an insulating member, to a device which is optionally installed for acoustical and/ or optical signalling.

References Cited UNITED STATES PATENTS 2,708,743 5/ 1955 Contri 73-146.3 XR

FOREIGN PATENTS 499,911 1/ 1939 Great Britain.

DONALD O. WOODIEL, Primary Examiner U.S. Cl. X.R. 

